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<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
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<body>
  <script>
    // 不允许同时声明同一个变量 更新变量如下
    // let age = 19
    // age = 20

    // 声明多个变量
    // 提倡单个声明
    let age = 20,name ='小明'
    console.log(age,name);
    
  </script>
</body>
</html>